The present invention is particularly concerned with improvements in non-metallic heating element assemblies and particularly electrically conductive carbon fiber heating element assemblies suitable for general purpose usage in a wide variety of heating applications.
The development of improved processes for artificially producing staple carbon in fibrous or filamentary form and at reasonable cost has virtually revolutionized the plastic composite industry, particularly where light weight and a high degree of mechanical integrity is desired. New materials embodying carbon in fibrous or filamentary form now enjoy wide spread use in the production of golf shafts, aircraft parts, and indeed entire airframes, to cite a few outstanding examples. Advantages in the use of carbon in the electrical field were early recognized by pioneers in that field, and although artificially produced carbon fiber has found some limited usage in electrically operated heating device, the potential for such usage has not yet been fully realized.
Accordingly, it is the general aim of the present invention to provide improved electrical heating element assemblies employing carbon fiber technology and suitable for supplying heat in a wide variety of environments both small and large. It is a further aim of the present invention to provide improved carbon fiber heating element assemblies for use in a variety of automotive heating applications as, for example, warming the seats and steering wheel of a vehicle, deicing and defogging windows, outside rear view mirrors and various vehicle engine heating applications.
A still further aim of the invention is to provide improved carbon fiber heating elements for economic installation and operation to heat large surface areas such as the floors of up-scale homes, apartments and condominiums, the surfaces of parking lots, sidewalks, driveways, highway sections, bridge decks and airport runways, as well as the surfaces of aircraft which operate thereon.
Yet another aim of the invention is to provide carbon fiber heating element assemblies, which utilizes to advantage the negative coefficient of electrical resistance (ohm) exhibited by carbon fiber.